The present invention relates to a molding system for molding plastics into desired finished products, and more specifically to such a molding system which has a leakage sealing and cooling water guide means to seal the gap and to guide cooling water in a spiral way.
FIG. 1 shows a molding system according to the prior art. This structure of molding system comprises a water circulation system 13' having a T-hole 130 for circulation of cooling water and a mounting groove 133' at the top, a bottom die 11' mounted on the water circulation system 13' and having a bottom blind hole 110', an upper die 10' controlled to mold a molding 12' with the bottom die 11', an O-ring 19' mounted in the mounting groove 133'on the water circulation system 13' and pressed below the bottom die 11', and a partition plate 14' mounted in the T-hole 130' and the bottom blind hole 110'. The partition plate 14' divides the T-hole 130' into a water inlet 131' and a water outlet 132', and defines a U-shaped water circulation passage 111' in the bottom blind hole 110' between the water inlet 131' and the water outlet 132' (see also FIG. 1A). This structure of molding system is still not satisfactory in function, and has numerous drawbacks as outlined hereinafter.
1. Because the O-ring 19' is directly mounted in the mounting groove 133' at the top of the water circulation system 13', it tends to be forced to displace by the bottom die 11' or the flowing flow of cooling water, causing a leakage.
2. The limited contact area between the O-ring 19', the bottom die 11' and the mounting groove 133' cannot effectively stop cooling water from passing out of the water circulation passage.
3. Because the water circulation passage 111' is a U-shaped passage, the temperature of water in the front half 15' of the water circulation passage 111' is relatively lower then that in the rear half 16' of the water circulation passage 111', thereby resulting in the bottom die 11' being unevenly cooled down.
4. Because the water circulation passage 111' is a U-shaped passage, cooling water passes through the water circulation passage 111' quickly, causing the bottom die 11' unable to be evenly and efficiently cooled down.